Berlin 2024 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 76: Superconductivity: Tunnelling and Josephson Junctions II

TT 76.1: Vortrag

Donnerstag, 21. März 2024, 15:00–15:15, H 3010

Chiral adiabatic transmission protected by Fermi surface topology — Isidora Araya Day^{1, 2}, •Kostas Vilkelis^{1, 2}, Antonio Lucas Rigotti Manesco², Ahmet Mert Bozkurt^{1, 2}, Valla Fatemi³, and Anton Akhmerov² — ¹QuTech, Delft University of Technology, Delft 2600 GA, The Netherlands — ²Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 4056, 2600 GA Delft, The Netherlands — ³School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853 USA

We demonstrate that Andreev modes that propagate along a transparent Josephson junction have a perfect transmission at the point where three junctions meet. The chirality and the number of quantized transmission channels is determined by the topology of the Fermi surface and the vorticity of the superconducting phase differences at the trijunction. We explain this chiral adiabatic transmission (CAT) as a consequence of the adiabatic evolution of the scattering modes both in momentum and real space. We identify an effective energy barrier that guarantees quantized transmission. We expect that CAT is observable in nonlocal conductance and thermal transport measurements. Furthermore, because it does not rely on particle-hole symmetry, CAT is also possible to observe directly in metamaterials.

Keywords: chiral adiabatic transmission; Fermi surface topology; quantised transmission; trijunction; andreev modes